Leave all the columns blank (empty) where you did Not have healthcare coverage through the Marketplace Exchanges.
If the program continues to give you an error after leaving the columns blank, then delete the Form 1095-A. After deleting the form, re-enter the form in the Health Insurance section manually. Do Not import the form.
Click on Tax Tools on the left side of the screen. Click on Tools. Click on Delete a form.
If you have other questions about this, ask in the comment section below.